Steve Brookes
Moderator
******At the request of others, this is a work in progress guide produced by members of the 964 register that will be continually updated. Please add your contributions to this thread and I will add them to the first post. The sub-headings are just suggestions. Others can be added. While compiling this guide errors are bound to creep in so please notify me of anything that you think might be an error. ******
964 Buyers' guide
The aim of this buying guide is to provide help to those searching for a 964. While it provides some key information about what to look out for when inspecting a car, it is not intended to replace a pre-purchase inspection (PPI). We always recommend that you commission a Porsche specialist garage or a recognised independent inspector as part of the buying process.
Other 964 buying resources
The following books on the 964 are recommended reading:
The Porsche 911 Enthusiast's Companion by Adrian Streather, Bentley Publishers (ISBN 0-8376-0293-9)
Ultimate Buyers' Guide "" Porsche 911 Carerra, Turbo & RS (964) by Peter Morgan, PMM Books (ISBN 0-9549990-4-5)
The following websites have an abundance of information about the 964, especially the history of the model, details of all the variants and technical specifications:
http://964uk.com/html/main.htm by Dave Wilkinson
http://www.porsche964.co.uk/ by John Miles
There is so much information about the various the timeline of the 964 and the variations of it in the resources above that there is no need to replicate that information here.
Identifying a 964
The chassis number (VIN) for a 964 produced for the rest of the world takes the form of:
WP0ZZZ96ZyS4bnnnn
The underlined letters vary as follows:
y = the model year letter (K=1989, L=1990, M=1991, N=1992, P=1993, R=1994
b = the body type number (e.g. 0 is often coupe but the numbers varied from year to year)
nnnn = unique serial number of the car
The VIN can be found in up to six places: 1. On the vehicle V5 document (logbook) 2. On an aluminium plate fixed to the right front wing inside the luggage compartment. 3. On a sticker fixed to the underside of the bonnet. 4. On a tab just below the petrol tank (behind the carpet). 5. On a sticker affixed to the service book. 6. On a plate inside the left A pillar that can be viewed through the windscreen (only on late production cars).
The engine number for a 964 takes the form of: 62ynnnnn
The underlined letters vary as follows:
y = the model year letter (K=1989, L=1990, M=1991, N=1992, P=1993, R=1994
nnnnn = unique serial number of the engine
The engine number can be found in 4 places: 1. On the vehicle V5 document (logbook) 2. As a stamp on the engine block (to the right of the engine fan at about 4 O'clock 3. On a sticker fixed to the underside of the bonnet. 4. On a sticker affixed to the service book.
The original colour of the car can be found in 4 places: 1. On the vehicle V5 document (logbook) 2. On a silver sticker fixed to the left front wing inside the luggage compartment. 3. On a sticker fixed to the underside of the bonnet. 4. On a sticker affixed to the service book.
The original equipment and specification for the interior fitted at the factory can be found on the bonnet and service book stickers.
Acknowledged Production Problems with 964s
Engine Oil Leaks
The 964 was originally designed with cylinder heads that were mounted without a head gasket set. However, it soon became apparent that oil would weep from the base of the cylinder heads so the design was changed during the 1991 model year (from engine number 62M06836). A fix was approved by Porsche for earlier engines but only the service records can indicate if this has been done (it was not a factory recall).
Double Mass Flywheel (DMF)
The DMF was introduced in model year 1990 and consists of two flywheels mounted together with the starter ring sandwiched between the two masses. The early DMF caused vibration in the transmission and problems with shifting gears. From 1992 Porsche fixed these problems: For the Carrera 4 a new secondary flywheel mass (the turbo version) was used and for the Carrera 2 an alternative supplier (LUK) was found for the DMF. Replacing the DMF on pre-1992 cars solved the problem and therefore most 964s will not suffer from this issue. Models such as the 964RS and 1989 model year Carrera 4s which had single mass flywheels did not suffer from these problems.
Dual Ignition System
The 964 came with a new dual ignition system where each cylinder was fitted with two spark plugs. This required two distributors where the secondary distributor was driven by a belt connecting it to the engine driven primary distributor. This belt is made from synthetic rubber and it failed quickly under the effect of Ozone created by the spark inside the distributor caps. Porsche fixed this problem by introducing a vent kit to remove the ozone from the assembly. It's a simple modification where a tube is attached between the base of the twin distributor and the heater blower ducting. In a very worst situation a broken secondary drive belt can cause expensive damage to the engine, hence the need to have the vent kit fitted and the belt changed periodically.
Rear Blower Fan Resistor
The rear blower assembly contains a blower fan ballast resistor (speed limiting device). This should be replaced with the newer version which contains overheat protection. If the new ballast resistor is not installed there is a risk of an engine bay fire.
Misting Rear Lights
Early rear light clusters are prone to condensation. Even though all the lights are vented via a pipe that is attached to the heater blower ducting, the early light design is still prone to condensation. The light clusters were later changed so that they had vented edges and the full light rubber gasket was replaced by side gaskets only. The rear lights can still be bought new but are only of the later design and should not be installed with the older full gasket.
Documentation
Service History
Engine and Transmission
Common Oil Leaks
Engine Mounts
If never replaced the standard engine mounts are likely to have leaked most of their hydraulic fluid and are no longer doing their job. It's easy to check them inside the engine bay - if you can get your thumb between the upper and lower part of a mount it will need replacing. Also check the engine carrier that the mounts are bolted to for cracks.
Exhaust System
The standard exhaust system consists of a cat (on the left hand side), primary silencer (long one across the back) and a final silencer (suit case shape on the right hand side). The cat can be replaced by a de-cat pipe. The flange on the heat exchanger where the cat bolts to is known to deteriorate over time (meaning a new heat exchanger is required). The primary silencer can be replaced by a 'Cup pipe'. The final silencer can be replace by a 'G pipe' or a 'J pipe'. Replacing original parts of the exhaust tends to make the car much louder. Trying to go back to original parts can be very expensive (used parts in good condition are difficult to find).
Oil pressure, Level and Temperature
When fully up to running temperature (about 15 minutes from cold) the pressure should be between 1 and 1.5 bar. When driving with the throttle open the pressure should read between 4 and 5 bar. Oil temperature will vary with climatic conditions and whether the car is on the move or sitting at idle. As a general guide the temperature needle will set on or around the first mark on the gauge (about 8 O'clock). To check that the oil thermostat is operating correctly, watch the temperature gauge needle in the first 10 to 15 minutes after firing up the car. It should rise slowly to the first main mark (8 O'clock) and then markedly drop back as the thermostat opens (allowing cool oil to flow from the front oil cooler). The level gauge is only reliable when the car is idling, on level ground at normal operating temperature. In this case the needle should sit nicely in the range shown on the display. The level gauge is of new use while the car is moving and throttle is being applied.
At What Mileage Should a 964 have an Engine Rebuild?
This is a subject that often prompts some lively debate because it is very much one that is down to personal experience. There are cars that have had rebuilds at less than 100K miles and cars that have had no major engine work that have done over 200K miles (and are still going strong). Some will argue that leakdown and compression tests will give you the answer as to whether the engine should have a rebuild but yet again, there does not seem to be a concensus of what results of such tests indicate that a rebuild must be done. However, one common fact is that a 20 year old engine (regardless of it being a 964), especially one that is dry-sumped, will have seals that are way beyond their best that are causing it to leak oil. So one of the main reasons an owner will have had the engine rebuilt is to get rid of all the leaks. If you can put up with a few drips of oil and the engine pulls well there's no reason to dismiss a car just because it's done more than 100K miles without a rebuild.
For those cars that are advertised that they have had a rebuild, look closely at the details of the invoice and who has done the work. Especially if it has only had a top-end rebuild. A full top end rebuild is very extensive if done properly (and consequently expensive). If the invoice only lists a set or piston rings, gaskets, a few sundries and labour it was no more than a sticking plaster job. The price of a thorough top-end rebuild is circa £4,000 (assuming nothing else needed doing at the same time). Add in a bottom end rebuild, the need to replace major components, numerous oil pipes and engine tinware when the work is done and that figure can easily rise to £8,000.
Tiptronic
Body
Common Rust Areas
1) Front and rear windscreen surrounds
2) Scuttle panel
3) Sills, beneath plastic covers
4) Front and rear wings where they meet the bumpers
5) Front and rear bumper mounting brackets
6) Engine tin
7) Rear light enclosures
8) Headlamp rings around the fastening screw (easy to replace)
Possibly less common
1) Rear arches where steel mounts for oil tank / seatbelt mounts have rusted
2) Front and rear jacking points
3) Headlight bowls
4) Front tub floor
5) Sills beneath original rubber kickplates
Spoiler Mechanism
Electrics
Central Locking
On key operated central locking systems where one or other of the front doors refuse to lock ie the button with the LED keeps popping back up,there can be 2 solutions amongst other more drastic problems.
1)Upgraded completely moulded plastic connecting links for the internal door mechanism are available to replace the composite metal/nylon ball jointed originals-the nylon ball section tends to split & then keeps slipping off its matching spherical matching part,which then prevents the door locking.
2)The lessor used door rotary internal knob mechanism tends to stiffen up,also its lubrication gets sticky.A quick solution entails ;removing the central trim in the knob,carefully using a small bladed screwdriver-remove the knobs central securing screw,then the knob & its' backing gasket & inject a good few squirts/sprays of WD 40, silicone etc type lubricant into the entire area behind the door card.Attach the knob without the screw & twist it right & left between the squirts,then refix in reverse order. This removes the extra friction that the solenoid has to overcome & which is just enough to otherwise stop the central locking work on that side.
Immobilizer
The immobiliser was normally retro-fitted at the supplying OPC using a kit manufactured & supplied by Hamilton & Palmer-Tel no 01732 760022 using a Receptor fitted to the steering wheel binnacle & a coded key with open brass contacts inserted into it normally giving 3 beeps when the ignition key must be inserted into the ignition switch fairly quickly & turned to start the engine.
If the beeps are not obtained,and/or the engine will not start,the immobiliser fob may have been withdrawn too soon or there is a problem with the immobiliser. See post #6 below by Vitesse for some ideas on fault finding.
Suspension
Upgrades
Wishbone Bushes
Wheels and Tyres
Options
Heating and Ventilation System
Interior
Seats
Water Leaks
One issue that can be common is damp carpets & underlay. The dampness appears to come from around the front/rear windows if there is a poor seal. It is a relatively simple/inexpensive job to reseal the frames but it takes ages to dry out the carpet. The underlay in particular can take, literally, months to dry out and it may be easier just to change it.
Brakes
Carrera 4 Specific
All Wheel Drive System
Brake Booster
Cabriolet Specific
Targa Specific
Leaking roofs are not uncommon. This is sometimes visible from water stains on the inside material of the roof, or on the inside of the doors and the extent of leakage may not always be apparent until you get caught driving in rain! Unless the roof has been restored professionally, the vinyl material will have shrunk and, if it's also spent a lot of its life folded up in the boot - become cracked, split or even torn. The shrinkage can cause the front lip of the vinyl to protude upwards and this can lead to a lot of wind noise at higher road speeds.
A new Targa roof is expensive - be prepared for a shock - and professional restoration isn't much cheaper. Also check that both of the roof 'removing handles' are with the car, otherwise you won't be able to take the Targa top off at all.
Turbo Specific
RS Upgrades
964s that have been turned into perfect 964RS replicas are few and far between. Mostly because of the complexity and huge expense that is involved. Some of the requirements like seam welding the shell, removing all of the underseal, fitting a manual steering rack and original RS ecu are not small tasks.
However, there are a number of popular 'RS upgrades' that can be added fairly easily (but are often quite costly). These include; the RS rear bumper section, the light weight RS clutch and flywheel, removal of the sound proofing, rear seats and fitting a lightweight carpet set, fitting lightweight door cards, RS rubber engine mounts and factory adjustable anti-roll bars. It should also be noted that the three spoke Clubsport steering wheel is often wrongly referred to as an 'RS steering wheel'. Similarly, 'RS brake ducts' were not an original fitment to the 964 RS (which had fog light blanks fitted). At the current time 'RS upgrades', done well, generally add to the value of the car.
964 Buyers' guide
The aim of this buying guide is to provide help to those searching for a 964. While it provides some key information about what to look out for when inspecting a car, it is not intended to replace a pre-purchase inspection (PPI). We always recommend that you commission a Porsche specialist garage or a recognised independent inspector as part of the buying process.
Other 964 buying resources
The following books on the 964 are recommended reading:
The Porsche 911 Enthusiast's Companion by Adrian Streather, Bentley Publishers (ISBN 0-8376-0293-9)
Ultimate Buyers' Guide "" Porsche 911 Carerra, Turbo & RS (964) by Peter Morgan, PMM Books (ISBN 0-9549990-4-5)
The following websites have an abundance of information about the 964, especially the history of the model, details of all the variants and technical specifications:
http://964uk.com/html/main.htm by Dave Wilkinson
http://www.porsche964.co.uk/ by John Miles
There is so much information about the various the timeline of the 964 and the variations of it in the resources above that there is no need to replicate that information here.
Identifying a 964
The chassis number (VIN) for a 964 produced for the rest of the world takes the form of:
WP0ZZZ96ZyS4bnnnn
The underlined letters vary as follows:
y = the model year letter (K=1989, L=1990, M=1991, N=1992, P=1993, R=1994
b = the body type number (e.g. 0 is often coupe but the numbers varied from year to year)
nnnn = unique serial number of the car
The VIN can be found in up to six places: 1. On the vehicle V5 document (logbook) 2. On an aluminium plate fixed to the right front wing inside the luggage compartment. 3. On a sticker fixed to the underside of the bonnet. 4. On a tab just below the petrol tank (behind the carpet). 5. On a sticker affixed to the service book. 6. On a plate inside the left A pillar that can be viewed through the windscreen (only on late production cars).
The engine number for a 964 takes the form of: 62ynnnnn
The underlined letters vary as follows:
y = the model year letter (K=1989, L=1990, M=1991, N=1992, P=1993, R=1994
nnnnn = unique serial number of the engine
The engine number can be found in 4 places: 1. On the vehicle V5 document (logbook) 2. As a stamp on the engine block (to the right of the engine fan at about 4 O'clock 3. On a sticker fixed to the underside of the bonnet. 4. On a sticker affixed to the service book.
The original colour of the car can be found in 4 places: 1. On the vehicle V5 document (logbook) 2. On a silver sticker fixed to the left front wing inside the luggage compartment. 3. On a sticker fixed to the underside of the bonnet. 4. On a sticker affixed to the service book.
The original equipment and specification for the interior fitted at the factory can be found on the bonnet and service book stickers.
Acknowledged Production Problems with 964s
Engine Oil Leaks
The 964 was originally designed with cylinder heads that were mounted without a head gasket set. However, it soon became apparent that oil would weep from the base of the cylinder heads so the design was changed during the 1991 model year (from engine number 62M06836). A fix was approved by Porsche for earlier engines but only the service records can indicate if this has been done (it was not a factory recall).
Double Mass Flywheel (DMF)
The DMF was introduced in model year 1990 and consists of two flywheels mounted together with the starter ring sandwiched between the two masses. The early DMF caused vibration in the transmission and problems with shifting gears. From 1992 Porsche fixed these problems: For the Carrera 4 a new secondary flywheel mass (the turbo version) was used and for the Carrera 2 an alternative supplier (LUK) was found for the DMF. Replacing the DMF on pre-1992 cars solved the problem and therefore most 964s will not suffer from this issue. Models such as the 964RS and 1989 model year Carrera 4s which had single mass flywheels did not suffer from these problems.
Dual Ignition System
The 964 came with a new dual ignition system where each cylinder was fitted with two spark plugs. This required two distributors where the secondary distributor was driven by a belt connecting it to the engine driven primary distributor. This belt is made from synthetic rubber and it failed quickly under the effect of Ozone created by the spark inside the distributor caps. Porsche fixed this problem by introducing a vent kit to remove the ozone from the assembly. It's a simple modification where a tube is attached between the base of the twin distributor and the heater blower ducting. In a very worst situation a broken secondary drive belt can cause expensive damage to the engine, hence the need to have the vent kit fitted and the belt changed periodically.
Rear Blower Fan Resistor
The rear blower assembly contains a blower fan ballast resistor (speed limiting device). This should be replaced with the newer version which contains overheat protection. If the new ballast resistor is not installed there is a risk of an engine bay fire.
Misting Rear Lights
Early rear light clusters are prone to condensation. Even though all the lights are vented via a pipe that is attached to the heater blower ducting, the early light design is still prone to condensation. The light clusters were later changed so that they had vented edges and the full light rubber gasket was replaced by side gaskets only. The rear lights can still be bought new but are only of the later design and should not be installed with the older full gasket.
Documentation
Service History
Engine and Transmission
Common Oil Leaks
Engine Mounts
If never replaced the standard engine mounts are likely to have leaked most of their hydraulic fluid and are no longer doing their job. It's easy to check them inside the engine bay - if you can get your thumb between the upper and lower part of a mount it will need replacing. Also check the engine carrier that the mounts are bolted to for cracks.
Exhaust System
The standard exhaust system consists of a cat (on the left hand side), primary silencer (long one across the back) and a final silencer (suit case shape on the right hand side). The cat can be replaced by a de-cat pipe. The flange on the heat exchanger where the cat bolts to is known to deteriorate over time (meaning a new heat exchanger is required). The primary silencer can be replaced by a 'Cup pipe'. The final silencer can be replace by a 'G pipe' or a 'J pipe'. Replacing original parts of the exhaust tends to make the car much louder. Trying to go back to original parts can be very expensive (used parts in good condition are difficult to find).
Oil pressure, Level and Temperature
When fully up to running temperature (about 15 minutes from cold) the pressure should be between 1 and 1.5 bar. When driving with the throttle open the pressure should read between 4 and 5 bar. Oil temperature will vary with climatic conditions and whether the car is on the move or sitting at idle. As a general guide the temperature needle will set on or around the first mark on the gauge (about 8 O'clock). To check that the oil thermostat is operating correctly, watch the temperature gauge needle in the first 10 to 15 minutes after firing up the car. It should rise slowly to the first main mark (8 O'clock) and then markedly drop back as the thermostat opens (allowing cool oil to flow from the front oil cooler). The level gauge is only reliable when the car is idling, on level ground at normal operating temperature. In this case the needle should sit nicely in the range shown on the display. The level gauge is of new use while the car is moving and throttle is being applied.
At What Mileage Should a 964 have an Engine Rebuild?
This is a subject that often prompts some lively debate because it is very much one that is down to personal experience. There are cars that have had rebuilds at less than 100K miles and cars that have had no major engine work that have done over 200K miles (and are still going strong). Some will argue that leakdown and compression tests will give you the answer as to whether the engine should have a rebuild but yet again, there does not seem to be a concensus of what results of such tests indicate that a rebuild must be done. However, one common fact is that a 20 year old engine (regardless of it being a 964), especially one that is dry-sumped, will have seals that are way beyond their best that are causing it to leak oil. So one of the main reasons an owner will have had the engine rebuilt is to get rid of all the leaks. If you can put up with a few drips of oil and the engine pulls well there's no reason to dismiss a car just because it's done more than 100K miles without a rebuild.
For those cars that are advertised that they have had a rebuild, look closely at the details of the invoice and who has done the work. Especially if it has only had a top-end rebuild. A full top end rebuild is very extensive if done properly (and consequently expensive). If the invoice only lists a set or piston rings, gaskets, a few sundries and labour it was no more than a sticking plaster job. The price of a thorough top-end rebuild is circa £4,000 (assuming nothing else needed doing at the same time). Add in a bottom end rebuild, the need to replace major components, numerous oil pipes and engine tinware when the work is done and that figure can easily rise to £8,000.
Tiptronic
Body
Common Rust Areas
1) Front and rear windscreen surrounds
2) Scuttle panel
3) Sills, beneath plastic covers
4) Front and rear wings where they meet the bumpers
5) Front and rear bumper mounting brackets
6) Engine tin
7) Rear light enclosures
8) Headlamp rings around the fastening screw (easy to replace)
Possibly less common
1) Rear arches where steel mounts for oil tank / seatbelt mounts have rusted
2) Front and rear jacking points
3) Headlight bowls
4) Front tub floor
5) Sills beneath original rubber kickplates
Spoiler Mechanism
Electrics
Central Locking
On key operated central locking systems where one or other of the front doors refuse to lock ie the button with the LED keeps popping back up,there can be 2 solutions amongst other more drastic problems.
1)Upgraded completely moulded plastic connecting links for the internal door mechanism are available to replace the composite metal/nylon ball jointed originals-the nylon ball section tends to split & then keeps slipping off its matching spherical matching part,which then prevents the door locking.
2)The lessor used door rotary internal knob mechanism tends to stiffen up,also its lubrication gets sticky.A quick solution entails ;removing the central trim in the knob,carefully using a small bladed screwdriver-remove the knobs central securing screw,then the knob & its' backing gasket & inject a good few squirts/sprays of WD 40, silicone etc type lubricant into the entire area behind the door card.Attach the knob without the screw & twist it right & left between the squirts,then refix in reverse order. This removes the extra friction that the solenoid has to overcome & which is just enough to otherwise stop the central locking work on that side.
Immobilizer
The immobiliser was normally retro-fitted at the supplying OPC using a kit manufactured & supplied by Hamilton & Palmer-Tel no 01732 760022 using a Receptor fitted to the steering wheel binnacle & a coded key with open brass contacts inserted into it normally giving 3 beeps when the ignition key must be inserted into the ignition switch fairly quickly & turned to start the engine.
If the beeps are not obtained,and/or the engine will not start,the immobiliser fob may have been withdrawn too soon or there is a problem with the immobiliser. See post #6 below by Vitesse for some ideas on fault finding.
Suspension
Upgrades
Wishbone Bushes
Wheels and Tyres
Options
Heating and Ventilation System
Interior
Seats
Water Leaks
One issue that can be common is damp carpets & underlay. The dampness appears to come from around the front/rear windows if there is a poor seal. It is a relatively simple/inexpensive job to reseal the frames but it takes ages to dry out the carpet. The underlay in particular can take, literally, months to dry out and it may be easier just to change it.
Brakes
Carrera 4 Specific
All Wheel Drive System
Brake Booster
Cabriolet Specific
Targa Specific
Leaking roofs are not uncommon. This is sometimes visible from water stains on the inside material of the roof, or on the inside of the doors and the extent of leakage may not always be apparent until you get caught driving in rain! Unless the roof has been restored professionally, the vinyl material will have shrunk and, if it's also spent a lot of its life folded up in the boot - become cracked, split or even torn. The shrinkage can cause the front lip of the vinyl to protude upwards and this can lead to a lot of wind noise at higher road speeds.
A new Targa roof is expensive - be prepared for a shock - and professional restoration isn't much cheaper. Also check that both of the roof 'removing handles' are with the car, otherwise you won't be able to take the Targa top off at all.
Turbo Specific
RS Upgrades
964s that have been turned into perfect 964RS replicas are few and far between. Mostly because of the complexity and huge expense that is involved. Some of the requirements like seam welding the shell, removing all of the underseal, fitting a manual steering rack and original RS ecu are not small tasks.
However, there are a number of popular 'RS upgrades' that can be added fairly easily (but are often quite costly). These include; the RS rear bumper section, the light weight RS clutch and flywheel, removal of the sound proofing, rear seats and fitting a lightweight carpet set, fitting lightweight door cards, RS rubber engine mounts and factory adjustable anti-roll bars. It should also be noted that the three spoke Clubsport steering wheel is often wrongly referred to as an 'RS steering wheel'. Similarly, 'RS brake ducts' were not an original fitment to the 964 RS (which had fog light blanks fitted). At the current time 'RS upgrades', done well, generally add to the value of the car.
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